Wheel chair construction



July 26, 1955 w. A. LI NQUIST 2,713,891

WHEEL CHAIR CONSTRUCTION Filed Jan. 2, 1955 2 Sheets-Sheet l IN VEN TOR.

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WHEEL CHAIR CONSTRUCTION Filed Jan. 2, 1953 2 Sheets-Sheet 2 IN VEN TOR.

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United States Patent Ofiiice WHEEL CHAIR CONSTRUCTION William A. Linquist, Minneapolis, Minn. Application January 2, 1953, Serial No. 329,247 2 Claims. (Cl. 155-452) My invention relates to improvements in portable invalids or wheel chairs. vention is the provision of a device of the class described having a frame structure, a seat mounted on the frame structure, a back rest pivotally secured to said frame rearwardly of said seat for pivotal movements from a substanopposite sides to facilitate access to and removal from w said seat, sick or invalid persons. Also, detachment of the arm rest elements from their normal positions permit collapsing of the back rest against the seat for .shipment or storage of the chair in a minimum of space.

Another object of my invention is the provision of a device of the class immediately above described, wherein the arm rest elements may be quickly attached and detached-and when attached will effect a rigid connection between the back rest and the frame structure.

A still further object of my invention is the provision of a device of the class above described which is extremely simple in construction, positive in its operation, pleasing in appearance, and inexpensive to produce.

The above and still further objects of my invention will become apparent from the following detailed specification, appended claims, and attached drawings.

Referring to the drawings, wherein like characters indicate like parts throughout the several views:

Fig. 1 is a perspective view of my novel device;

Fig. 2 is a view corresponding to Fig. 1 with some parts removed and other parts shown in different positions;

Fig. 3 is an enlarged fragmentary view in side elevation of a portion of the frame and back rest of my invention, some parts being broken away and some parts shown in section;

Fig. 4 is a fragmentary detail in rear elevation as seen from the line 44 of Fig. 3;

Fig. 5 is an enlarged fragmentary section taken substantially on the line 5-5 of Fig. l with some parts removed; and

Fig. 6 is a fragmentary detail in front elevation as seen from the line 66 of Fig. 1.

Referring with greater particularly to the drawings, the numeral 1 indicates in its entirety a frame structure made up of laterally-spaced vertically disposed generally rectangular members 2, preferably formed from tubular steel or the like. The lower horizontal'bar 3 of each member 2 is connected by a transverse brace member 4 in spaced relation to the forward ends thereof and by a transverse axle-forming member 5 adjacent their rear ends. The opposite ends of the axle member 5 project laterally out I The primary object of my inj 2,713,891 Patented July 28, i955 wardly of the members 2, and have rotatably mounted thereon a pair of large drive wheels 6, preferably equipped with rubber tires 7. Stub legs 8 depending from the forward ends of the bottom bars 3 of the frame 2 are equipped with caster wheels 9, also preferably having rubber tires thereon. Mounted on the frame 1 and spanning the upper bars 10 of the frame 2 is a seat 11 which is spaced forwardly sufficiently with respect to the drive wheels 6 to allow access thereto either from the front or the side, under conditions hereinafter to be described.

The pivotally mounted foot supporting platform 12 and the cam acting manually operated braking mechanism 13 form no part of the instant invention and will not be described in detail.

A back rest 14, shown as including an inverted generally U-shaped back rest frame 15 and a cushion 16, has the lower end portions of its legs 17 pivotally received, as indicated at 18, between the opposite sides 19 of a pair of upstanding forwardly opening generally U-shaped hinged brackets 20 rigidly secured, by welding or the like, to the upper ends of the horizontal bars 10 of the frame structure 2 rearwardly of the seat 11. As shown in Fig. 2, the back end portions of the U-shaped mounting brackets 20 are identified by the numeral 21. This arrangement makes possible pivotal swinging movements of the back rest 14 from a substantially upright operative position, wherein the legs 17 are in engagement with the back portions 21 of the U-shaped brackets 20, as indicated in Fig. l, to the inoperative position in engagement with the seat 11, as shown in Fig. 2, wherein the structure is reduced to a minimum size for shipping or storage. A pair of elongated arm rest elements 22 are shown as cornprising generally horizontal bars 23, upon which are mounted the arm engaging pads 24, and depending forward end portions 25. At their rear end portions, the horizontal members 23 are inturned to provide opposed trunnions 26 which are adapted to be snugly but rotatably received within aligned key-hole openings 27 in ears 28 projecting rearwardly from the legs 17 of the back rest frame 15, above the pivotal connection 18. It will be noted that the trunnions 26 are provided with keyacting pins 29 which project from opposite sides of the trunnions 26, and are insertable in the key-hole openings 27 only when the arm rest elements 22 are in operative dotted-line position of Fig. 3. It will vbe noted that when the arm rest elements 22 are moved to the operative fullline position of Fig. 3, the pins 29 securely lock the trunnions 26 in the position of Fig. 4-in which position the depending forward end portions are in a position to be securely locked to the frame structure 2 adjacent opposite sides of the forward end portion of the seat 11. More specifically, this attachment includes a pair of outwardly projecting arms 30, to the outer ends of which are rigidly secured upwardly opening U-shaped sockets 31 which are adapted to receive the flattened lower end portions 32 of the depending forward end portions 25 of the arm rest elements 22. It will be noted that the flattened ends 32 are provided with slots 33 which preferably converge inwardly to provide a restricted mouth 34 for circular openings 35. Extending transversely of the U-shaped sockets 31 and journalled therein for rotation are keys 36. Handle members 37 are provided for imparting rotation to the keys 36. It will be noted that the keys 36 have a thickness which enables them to be inserted into the circular openings 35 in the flattened end portions 32; whereas they have width corresponding approximately to the diameters of the openings 35. By reference particularly to Fig. 5, it will be noted that rotating of the handle 37 to a substantially horizontal position will permit the keys 36 to enter the openings 35 through the restricted mouths 34 thereof; whereas rotation of the hane.) dles 37 to a vertical position securely locks the keys 36 within said openings 35.

It should be obvious from the above that when the arm rest elements 22 are removed from their operative posi tions, as shown in Fig. 2, a maximum of space and convenience is provided for placing an invalid upon the seat 11 or removing him therefrom. Also, the device may be at least partially collapsed for the purpose of shipment and storage. On the other hand, the arm rest elements 22 may be quickly secured in operative position for use by the patient once he has been positioned upon the seat 11, and the frame 2 and back rest 14 rigidly and safely tied together.

While 1 have shown a commercial embodiment of my invention, it should be obvious that same is capable of modification without departure from the scope of the invention as defined by the appended claims.

What I claim is:

1. In a wheel chair, a frame structure, a horizontally disposed seat on said frame structure, a back rest frame pivotally secured on a horizontal axis to said frame structure rearwardly of said seat for swinging movements of the former from a substantially vertical operative position to an inoperative position toward engagement with said seat, means positively limiting rearward swinging movements of said back rest frame from its substantially vertical operative position, a pair of elongated arm rest elements, means for detachably securing the rear end portions of said elements to opposite sides of said back rest frame above the pivotal connection thereof with said frame structure, and means for detachably securing the front end portions of said elements to said frame structure on opposite sides of and adjacent the front end portion of said seat, said first-mentioned means including a pair of opposed key-equipped trunnions on the rear end portions of said arm rest elements adapted to be rotatably received in aligned apertures in said back rest frame, and said last-mentioned means including a pair of horizontally-disposed rotatable keys one each on opposite sides of said frame structure and adapted to be received within key-hole openings in the lower end portions of said elements upon forward pivotal movements of said trunnions in their cooperating openings, partial rotation of said keys positively locking said last-mentioned keys in said slots, said trunnions being positively locked in their cooperating key-hole openings when said last-mentioned keys are received within said key-hole slots.

2. The structure defined in claim 1 in which the front end portions of said arm rest elements are flattened for reception between upwardly opening U-shaped sockets on opposite sides of said seat, said rotatable keys extending transversely through said U-shaped sockets, said keyholes being located within said flattened end portions and opening downwardly thereof in inwardly converging slots, and which feed said keys to restricted circular openings.

eferenees Cited in the file of this patent UNITED STATES PATENTS 

